Dental instrument.



F. H. SKINNER. DENTAL INSTRUMENT.

APPLICATION FILED SEPT. 2,1908.

Patented Sept. 9, 1913.

UNITED STAWENT OFFICE" FRANK H. sK'IN'NER, or Ga ma. I LINO S.

nearer msraarrarr,

Specification oii Letters retent- Application flier September 2; 190aseriai m). 451.3135.

fore provided, and which shall be capable of removing crown pins from front or back teeth with equal facility.

The pin or post pullers heretofore provided have comprised vise or forceps jaws and a post or prong movable parallel tosaid jaws which has required positioning of the tool in line with the axis of the tooth operated upon, an arrangement extremely inconvenient or impossible in the case of the molars.

One of the objects of the present invention is to provide a pin extractor which shall be equally accessible to all the teeth in a patients mouth. To accomplish this I have provided a tool the body of which may, during operation, be held at right angles to the persons face in the usual manner, while the cooperating beaks and post alone are movable, as usual, parallel with the axis of the tooth or the crown pin to be removed therefrom. I also provide a construction adapted to utilize a very short post,one

which may be freely moved between, as well as in alinement with, upper and lower teeth, while, on the other hand, the body of the tool is held in the most advantageous position for manual manipulation. namely, at right angles to the patients face.

With the above-named general objectsin view my invention consists in the novel construction, combination and arrangement of parts hereinafter described in detail, illus trated in the drawing and incorporated in the appended claims.

In the drawing-Figure 1 is an elevation of a dental instrument embodying my invention. Fig. 2 is a longitudinal section thereof taken in a plane at right angles to the plane of Fig. 1. Fig. 3 is a' section taken on line XX of Fig. 2. Figs. 4 and 5 are enlarged detail views shown in perspective.

the several views 2' and 3 represent the handles of a pair of forceps provided with a clamping screw 4 secured at ate the handle 2- and having its threaded portion 6 extending throughbore; inthe handle The crew 4 is provided with a thumb nut 7 which when turned up against the handle 3 forces the handles together in the closing mevemeat of the jaws 8 and 9 pivoted together at 10. These jaws areprovided with nits beaks if and'12 which pr ject atan angle from the jaws 8' 9. The opening and closing movement of the beakstherefore takes place in a name intersecting the plane cf meveraeat e eh-aims proper at substantially or approximately right angles.

1 In practice the beaks are made less than "an inch in length, and the length of the post in my improved construction is substantially confined to the length of the beaks;

The post 13 is mounted between the beaks 11 and 12 to move parallel therewith and the part thereof which is brought to bear upon the root of a tooth may be either a single contact point, or, and preferably, two contact points or prongs 14 and 15 which straddle a crown pin and distribute the strain of pressure against the root equally on both sides of the pin and the axis of the tooth 16 shown in dotted lines in Fig. 2. The pin 17 (also shown by dotted lines) is gripped bythe beaks 11 and 12 and the post 13 is then advanced againstthe root of a tooth, thereby producing the reciprocal forces of pulling and pushing, acting only on the pin and tooth and without straining the peridental membrane, in the following manner. Power is applied through the usual screw 18 mounted in an opening 19 through the unthreaded portion of the clamping screw 4 and having threaded engagement with the nut 20 secured to the handle 2. The force of the screw is transmitted to a coupling piece 21 in which are secured the ends of a yoke, fork, or doubled bar 22. The bend of the latter is formed into a cam 23 having oppositely disposed cam surfaces 24 and 25 engaged by an eye 26 in the post 13. As the cam surfaces strike the opposite sides of the eye at a slant as the bar 22 is advanced the post is forced forward by the cam surface 24, while on the return movement of the bar the opposite surface 25 retracts the post. The two arms of the rod 22 straddle the forceps jaws and are slidably' mounted in shallow grooves 27 30 of the jaw S'embracing the jaw 9. The

screw 18 is provided with a thumb piece 31 with the aid of which the screw is manipulated. As shown in Fig. l, the post is supported laterally in the direction of move ment of the cam member by the beaks 11 and 12. At right angles to said direction of movement the post is supported laterally by its body portion which passes between the beaks.

I claim as my invention 1. The combination with a pair of movable jaws, of beaks projecting laterally from said jaws, a post cooperating with said beaks, and means for advancing said post at an angle to said jaws.

2. The combination with a pair of movable jaws, of a post, means for moving same at an angle to said jaws, beaks cooperating with said post, and means for actuating said jaws and beaks.

3. The combination with a pair of movable jaws having laterally projecting beaks, of a Copies of this patent may be obtained for five cents each, by addressing the Commissioner Washington. D. G.

part movable between said beaks and adapted to rest upon the root of a tooth, and means movable parallel to said jaws for moving said part.

4. The combination with relatively movable jaws, of beaks therefor, and a post having a part or parts adapted to rest upon the root of a tooth, said post mounted to move at an angle to said jaws.

5. The combination with a pair of forceps having side-gripping nibs or beaks, of a post mounted to move along said beaks, a screw and cam arranged to movesubstantially at right angles to said posts direction of movement, and means for clamping said beaks upon a crown pin and the like.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

FRANK H. SKINNER.

Witnesses:

EDWARD P. SKINNER, C. G. NOYES.

of Patents, 

